This isn't a thorough testing, just some thoughts' on what I've seen so far.
 
The update/rollback installed smoothly and without error.
 
Upon launching SONAR I was presented with this message:
 

 
I closed the message and continued loading a new project created in 2016.11 and it appeared that all of the plugin categories and names were present so I don't know what triggered the Database Error
 
Digging a little deeper, it was clear that several plugins were missing, notably the LP EQ and the LP MB
 
I did a plugin reset and rescan and all plugins were now listed.
 
I then closed this project and opened an earlier one which behaved horribly in 2016.11
It opened without error and I managed to add several plugins which caused the earlier grief - Rapture Pro, X3TA+2, CA-2A
 
So I'm giving this release a guarded thumbs up

Had the same issue,
thanks for pointing this out.

similar errors reported on steam in october:
http://steamcommunity.com/app/380080/discussions/2/350543951937650185/

I get this every time SONAR "flakes" out

I loves my cookies half baked;
my DAW, not so much!
 2016.11 is "cooking" here for me!
T

Bristol, I got that database error the first time I launched Sonar after the 11 update (updated from 8.)  Didn't seem to affect anything and the second time I launched it, there was no error.

I already reported this here http://forum.cakewalk.com/Database-Error-m3529904.aspx
 
CW is looking into it. 

Just an Update;
Due to my "issues" with 12, I rolled back to 2016.10
The "save as" crash raised its ugly head again.
Fortunately "Fault Reporter" did not flake out, and there is a CWBRN in the system.
Bear in mind I had been running 2016.10 and 2016.11 without issue on this machine (Win7x86).
2016.11 continues to run flawlessly on my Cat (Win7x64), but I have not installed 2016.12.
Although, I had to re-scan VST plugins to find Ozone 7 a day or 2 ago; I'm sure I've used it since the 11 update.
Maybe not?
Net result, I rolled Windows back to my last image (11-27-2016);
SONAR 2016.10 build 19 appears to be "stable" now.
Evidently not all the recent problems are Win 10 update related...
 
T
 

When moving data, don't use "Slide over to Make Room"...it's broken. Do only "Blend Old with New" or "Replace Old with New." I realize this affects only a small group of people but it's a particularly pernicious bug that splits clips in unexpected places and causes other mischief.
 
Aside from that, everything else is working here on three very different machines (Gibson office, studio, and home office "studio B"). I haven't done a reset/rescan yet but will if I notice any plug-ins missing.

I got this same "Database Connection Failed" error message upon initial startup, after installing the latest early release.  After re-starting, everything appeared to be fine.  Haven't noticed any missing plugins.

I'm on Win 7 Pro, and had this same error after updating.